s 


UNITED  STAT 


T  OF 


BULLETIN  No.  706 

Contribution  from  the  Bureau  of  Chemistry 
CARL  L.  ALSBERG,  Chief 


Washington,  D.  C. 


Issued  July  26,  1918;  Revised  November  6,  1920. 


AMERICAN  SUMAC:  A  VALUABLE  TANNING 
MATERIAL  AND  DYESTUFF. 

JBy  F.  P.  VEITCH,  Chemist  in  Charge,  J.  S.  ROGERS  and  R.  W.  FREY,  Assistant 
1 1  Chemists,  Leather  and  Paper  Laboratory. 


CONTENTS. 


Page. 

tntroduction 1 

Species   of  American    sumac 3 

iPresent    methods    of    gathering    and 

curing . 5 

innin  content 8 

imac   extract  _.  9 


Page. 

Disposal  of  extracted  material 10 

Causes  of  poor  quality  in  sumac 11 

Cooperation    for   better   sumac 11 

Directions  for  gathering  and  curing 12 

Buyers  of  sumac 12 

Summary 13 


INTRODUCTION, 

Sumac,  known  also  as  s"  shumac  "  or  "  shoemake,"  is  a  wild  plant 
[rich  in  tannin,  a  product  of  value  to  the  tanning  and  dyeing  indus- 
tries. Sumac  grows  on  ^uncultivated  lands  in  many  parts  of  the 
[United  States  and  is  particularly  abundant  and  accessible  east  of 
the  Mississippi.  Plentiful  stands  occur  on  cut-over  land,  in  old 
[fields  and  pastures,  on  mountain  sides,  in  waste  places,  and  on  the 
[edge  of  swamps  in  the  Appalachian  region.  Immense  quantities  of 
this  valuable  tanning  and  dyeing  material,  which  cost  nothing  to 
[raise,  remain  ungathered  every  year,  and  are  allowed  to  go  to  waste, 
the  United  States  imports  annually  more  than  $5,000,000*  worth 
|of  vegetable  tanning  materials. 

Although  there  would  seem  to  be  little  excuse  for  such  an  un- 
>nomic  condition,  a  study  of  the  situation  reveals  certain  obstacles 
[in  the  way  of  making  use  of  this  sumac  for  the  purposes  to  which 
it  is  adapted.  It  is  hoped,  however,  that  these  difficulties  may  be 
overcome  by  the  manufacturers  and  gatherers  if  they  have  a  fuller 
1  realization  of  the  possibilities  of  native  sumac.  The  domestic 

[sumac  industry  is  well  worth  organization  ard  development  as  a 

— — __ — . _ 

1  Foreign  Commerce  and  Navigation  of  the  United  States,  1916,  U.  S.  Department  of 
>mmerce. 


3436° — 20 


444109 


BULLETIN   706,   IT.   S.   DEPARTMENT   OF  AGRICULTURE. 


the  present  none  too  plentiful  supply  of  tanning 
materials,  'of  lessening  our  dependence  on  foreign  countries,  and  of 

**>  «giva2£.llie:pe3dre  *in»  the  rural   districts  an   additional  source  of 
«-  ^•eJ-rv^!»,«    i.e,r.«*  •  ." 
income. 

Sumac  leaves  have  long  been  used  in  tanning  leather  and  in  dye- 
ing fabrics.  The  value  of  sumac  for  tanning  depends  chiefly  upon 
the  fact  that  it  yields  durable  light-colored  or  white  leathers,  as  a 
consequence  of  which  it  is  employed  largely  in  the  tanning  of  book- 
binding, glove,  and  hatband  leathers,  and  for  removing  darker 
colored  tanning  materials  from  the  surface  of  bag,  case,  and  fair 
harness  leathers.  Sumac-tanned  leathers  have  been  found  to  be 
most  durable  and  suitable  for  bookbindings  and  other  purposes, 
where  the  leather  must  last  indefinitely.  The  greater  part  of  the 
gathered  American  sumac,  however,  is*used  in  the  dyeing  of  cotton 
goods. 

The  sumac  industry  in  the  United  States  is  of  direct  interest  to 
the  country  people  of  certain  sections.  It  is  largely  a  rural  industry, 
since  the  sumac  is  harvested  and  cured  by  the  country  people  and 
is  sold  through  country  dealers  for  grinding  or  for  the  manufacture 
of  extract. 

In  recent  years  the  quantity  of  sumac  gathered  has  been  much 
smaller  than  formerly.  Cheaper  materials  for  making  light- 
colored  leathers  are  in  use,  while  the  demands  of  dyers  have 
not  been  large.  American  sumac,  owing  to  careless  gathering  and 
curing,  yields  a  darker  colored  leather  than  the  sumac  imported  from 
Sicily,  and,  since  sumac  is  used  for  tanning  light-colored  leathers, 
this  quality  renders  the  American  product  less  desirable  and  de- 
creases the  demand  for  it.  Another  reason  for  the  small  amount 
collected  is  that  the  gatherers  often  earned  less  than  could  be  made 
at  other  kinds  of  work. 

While  it  is  true  that  American  sumac,  if  properly  handled,  will 
make  an  excellent  substitute  for  Sicilian  sumac,  consumers  of  sumac 
must  realize  that  the  first  step  necessary  for  the  production  of  a 
high-grade  sumac  similar  to  the  foreign  article  is  proper  gathering 
and  proper  curing,  which  can  be  accomplished  only  by  offering  as 
an  incentive  a  price  commensurate  with  the  labor  and  the  quality 
of  the  product.  The  better  the  sumac  the  better  should  be  the  price. 
In  this  way  mutual  benefit  will  be  gained  and  much  will  be  done 
toward  materially  developing  the  domestic  sumac  industry. 

Statistics  probably  do  not  indicate  accurately  the  quantity  of 
sumac  gathered  in  the  United  States,  because  careful  records  are  not 
kept  by  gatherers  and  dealers  of  the  amounts  collected  and  used. 
The  figures  for  domestic  production  given  in  Table  1  were  compiled 
from  the  Census  reports,  and  the  figures  for  the  imports  from  the 


AMERICAN   SUMAC. 


reports  on  commerce  and  navigation  of  the  United  States,  issued  by 
the  United  States  Department  of  Commerce. 

TABLE  1. — Production  of  sumac  in  the  United  States. 


Yea'r. 

Sumac  extract. 

Ground  sumac. 

Quantity. 

Value. 

Quantity. 

Value. 

1899.. 

Pounds. 
3,349.742 
4.093,619 
3,  148,  790 
4,512,361 

$103,085 
95,  958 
107,  456 
129,  631 

Pounds. 
9,284,000 
5,061,333 

$114,660 
65,  190 

1904. 

1909 

1914  

1 

TABLE  2. — Importation  of  sumac  into  the  United  States. 


Year. 

Sumac  extract  (imported 
for  consumption). 

Ground  sumac  (general 
importation). 

Quantity. 

Value. 

Quantity. 

Value. 

1894 

Pounds. 
1.  277,  609 
1,266,542 
1,356,020 
1,  232,  830 
1,461,373 
987,348 
1,389,733 
1,270,825 
1,029,792 
727,  449 
36,003 

$54,  533 
48,399 
50,681 
54,  171 
54,  899 
36,  025 
46,  551 
44,568 
42,  973 
35,066 
4,108 

Pounds. 
8,383,570 
12.975,970 
18,604,644 
10,974,613 
13,632,861 

$192,647 
183,  136 
276,891 
293,249 
299,170 

1899  

1904 

1909  

1910." 

1911 

1912.. 

12,498,376 
14,489,776 
10,770,400 
13,  165,  182 
21,542,390 
11,637,023 
10,557,920 
9,311,055 

235,  154 
297,506 
258,  738 
323,  448 
555,276 
365,  173 
355,  192 
307,843 

1913 

1914  

1915. 

1916 

1917 

1918 

23,906 

2,116 

1919 

Information  in  the  possession  of  the  Bureau  of  Chemistry  shows 
clearly  that  the  consumption  of  domestic  sumac  during  the  two  or 
three  years  prior  to  1917  was  more  than  10,000,000  pounds  annually. 
Early  in  1910  domestic  sumac  was  quoted  at  $55  a  ton.  In  June, 
1920,  Sicilian  sumac  was  worth  about  $90  a  ton  at  the  chief  Atlantic 
ports,  while  domestic  sumac  was  quoted  at  $75  a  ton. 

SPECIES  OF  AMERICAN  SUMAC. 

Important  species  of  sumac  growing  in  North  America  are :  Dwarf 
sumac  (Rhus  copallina  L.),  white  sumac  (Rhus  glabra  L.),  and  stag- 
horn  sumac  (Rhus  hirta  (L.)  Sudw.).  Other  species  which  contain 
tannin  are :  Fragrant  sumac  (Rhus  aromatica  Ait.),  American  smoke 
tree  (Rhus  cotinoides  Nutt.),  and  coral  or  Jamaica  sumac  (Rhus 
metopium  L.) .  Two  species  of  sumac  are  poisonous,  namely :  Poison 
sumac,  or  poison  elder  (Rhus  vernix  L.),  and  poison  or  three-leaf  ivy 
(Rhus  radicans  L.). 

DWARF  SUMAC,  sometimes  called  BLACK  or  MOUNTAIN  SUMAC  (Rhus 
copallina) . — A  shrub  or  sometimes  a  small  tree  with  maximum  height 


4  BULLETIN   706,   U.   S.   DEPARTMENT   OF   AGRICULTURE. 

of  30  feet  and  trunk  diameter  of  10  inches.  The  leaflets  are  dark 
green,  smooth  on  top,  paler  and  often  hairy  underneath,  with  edges 
smooth  or  few-toothed  toward  the  apex.  The  fruit  grows  in  dense 
terminal  clusters,  is  crimson  in  color,  and  is  covered  with  fine  hairs. 
The  unmistakable  characteristics  of  this  species  are  the  winged 
growth  along  the  leaf  stem  between  the  leaflets  (PI.  II,  A)  and  the 
black  specks  on  the  new  stalk.  Dwarf  sumac  grows  in  dry  soil,  and 
may  be  found  from  Maine  and  southern  Ontario  to  Florida  and 
Texas,  and  west  to  Minnesota  and  Nebraska. 

WHITE  SUMAC,  sometimes  called  SMOOTH,  UPLAND,  or  SCARLET 
SUMAC  (Rhus  ylabra) . — A  shrub,  or  rarely  a  small  tree,  2  to  20  feet 
high.  The  leaflets  are  dark  green  on  top  and  whitish  underneath, 
with  edges  sharply  saw-toothed.  The  fruit  grows  in  dense  terminal 
clusters,  and  is  covered  with  short  reddish  hairs.  The  distinguishing 
characteristics 'of  this  species  are  the  smoothness  of  the  stalks  and 
leaf  stems,  together  with  a  bluish  white  bloom,  a  powdery  film  similar 
in  appearance  to  that  found  on  plums,  which  covers  the  stalks  and  the 
under  side  of  the  leaflets  (PL  III).  White  sumac  grows  in  dry  soil 
from  Nova  Scotia  to  British  Columbia,  and  south  to  Florida,  Missis- 
sippi, and  Arizona. 

STAGHORN  SUMAC,  sometimes  called  HAIRY  SUMAC  (Rhus  hirta).— 
A  shrub,  or  small  tree,  with  maximum  height  of  40  feet  and 
trunk  diameter  of  9  inches.  Leaflets,  dark  green  and  nearly  smooth 
on  top,  pale,  and  more  or  less  hairy  underneath,  with  edges  sharply 
saw-toothed.  The  fruit,  which  grows  in  dense  terminal  clusters,  is 
thickly  covered  with  bright-crimson  hairs.  The  distinguishing 
characteristic  of  this  species  is  the  hairy  growth  along  the  stalks  and 
leaf  stems  (PL  IV) .  Staghorn  sumac  is  found  in  dry  and  rocky  soils 
from  Nova  Scotia  to  Georgia,  especially  among  the  mountains,  and 
as  far  west  as  southern  Ontario,  Minnesota,  Missouri,  and  Mississippi. 

Since  poison  sumac  sometimes  is  mistaken  for  the  more  common 
species,  and  its  poisonous  effects  are  usually  very  severe,  it  seems 
desirable  to  describe  it  as  an  aid  in  distinguishing  poison  sumac 
from  the  other  species. 

POISON  SUMAC,  sometimes  called  POISON  ELDER  (Rhus  vernix).— 
A  shrub,  or  small  tree,  with  maximum  height  of  28  feet  and  trunk 
diameter  of  6  inches.  The  leaflets  are  green  on  top  and  underneath, 
with  edges  smooth.  The  fruit,  which  grows  in  loose,  open  clusters, 
consists  of  smooth  white  or  light  gray  berries.  It  should  be  noted 
that  poison  sumac  differs  decidedly  from  the  important  species  in 
the  color  and  cluster  formation  of  its  fruit.  Furthermore,  it  may 
be  easily  distinguished  from  the  dwarf  sumac  by  the  absence  of  the 
winged  growth  along  the  leaf  stems,  and  from  the  white  and  stag- 
horn  sumac  by  its  smooth-edged  leaflets  (PL  V).  Poison  sumac 
almost  invariably  is  found  in  swamps.  It  grows  from  southern 


AMERICAN   SUMAC.  5 

Ontario  and  near  the  eastern  coast  in  the  Eastern  and  Middle 
States,  south  to  Florida,  and  west  to  Minnesota,  Missouri,  and 
Louisiana. 

PRESENT  METHODS  OF  GATHERING  AND  CURING. 

COMMON    NAMES    USED   BY    GATHERERS. 

Sumac  is  commonly  termed  by  the  gatherers  either  "black"  or 
"  white."  "  Black  "  sumac  refers  to  dwarf  sumac  (Rhus  copallina) , 
and  "white"  sumac  usually  means  white  sumac  (Rhus  glabra),  al- 
though it  is  believed  that  this  term  is  sometimes  applied  also  to  stag- 
horn  sumac  (Rhus  hirta).  Staghorn  is  not  so  extensively  gathered 
as  white  sumac.  In  some  sections,  as  in  eastern  Virginia,  only  black 
sumac  is  collected,  while  in  others,  such  as  the  western  part  of 
Virginia  and  in  West  Virginia,  Maryland,  and  Pennsylvania,  small 
quantities  of  white  sumac  also  are  gathered. 

KINDS  AND   CONDITION   OF  SUMAC  DESIRED   BY  EXTRACT  MANUFACTURERS. 

Dwarf,  or  black,  sumac  is  the  only  variety  desired  by  extract 
makers,  other  species  being  refused  because,  it  is  stated,  they  contain 
a  much  higher  proportion  of  pithy,  milky  stalks,  and  yield  less  ex- 
tract. '  All  contracts  with  gatherers  specify  that  the  sumac  shall  be 
dwarf,  or  black,  only.  The  leaves  and  stems  of  the  sumac  alone  are 
of  value.  The  stalk  is  useless.  While  small,  short  new-growth  stalks, 
broken  off  close  below  the  leaf  stem,  may  be  accepted  by  the  buyer, 
the  chances  are  that  they  will  be  refused  or  received  at  a  reduction  in 
price.  Gatherers  are  advised  to  take  particular  pains  to  see  that 
their  sumac  contains  very  little  stalk  and  no  berries.  Berries  are  of 
no  value  to  extract  makers. 

PROPER  TIME  TO  GATHER. 

Extract  makers  are  opposed  to  the  early  gathering  of  sumac,  even 
though  the  leaves  apparently  are  mature.  They  state  that  the  leaves 
gathered  in  May  and  June  are  light  in  weight,  do  not  yield  as  much 
extract,  and  can  not  be  handled  as  well  in  the  extracting  process. 
From  the  viewpoint  of  both  gatherers  and  extract  makers,  the  best 
time  to  gather  sumac  is  in  July,  August,  and  September.  Gathering 
should  not  be  done  after  frost,  as  the  leaves  then  drop  off  readily  and 
the  color  of  the  extract  made  from  red  leaves  is  darker  and  less 
desirable  than  that  made  from  light-colored,  well-cured  leaves. 

YIELDS    PER    ACRE. 

While  sumac  is  very  plentiful,  especially  in  the  eastern  United 
States,  it  rarely  covers  thickly  an  area  of  any  extent,  but,  inter- 
mingled with  other  vegetation,  grows  rather  scattered  in  patches 


6  BULLETIN   706,   U.    S.   DEPARTMENT   OF   AGRICULTURE. 

along  old  fence  rows,  and  on  cut-over  and  burned-over  woodland. 
Eeports  have  been  received  that  in  certain  sections  it  grows  thickly, 
unmixed  with  other  growth,  and  in  sufficient  areas  to  permit  cutting 
with  a  mowing  machine.  Several  cases  of  clean  stand  have  been 
reported,  but  they  have  not  come  directly  to  the  attention  of  the 
Bureau  of  Chemistry.  A  report  has  been  received  from  eastern 
Virginia  of  a  tract  of  from  10  to  15  acres  of  burned-over  and  cut-over 
land  from  which  5  tons  of  dwarf  sumac  (leaves,  leaf  stems,  and  cur- 
rent year's  stalk)  were  gathered.  An  estimate  by  the  bureau,  based 
on  white  sumac  gathered  from  a  plot  20  by  30  feet,  gave  a  calculated 
yield  per  acre  of  4,864  pounds  (green  weight).  This  would  make 
about  1,600  pounds  of  cured  sumac. 

QUANTITY  A  MAN  CAN  GATHER  IN  ONE  DAY. 

Many  factors  may  influence  the  quantity  a  man  can  gather.  Some 
of  these  are  the  experience  and  alacrity  of  the  gatherer,  availability 
or  lack  of  teams  for  hauling,  growth  of  sumac — whether  dense  or 
scattering — species  of  sumac  collected,  and  whether  leaves,  leaf  stems, 
and  stalks,  or  only  leaves  and  leaf  stems  are  gathered.  The  sumac 
collected  by  one  man  in  one  day  may  weigh  from  150  to  600  pounds 
when  dried,  but  averages  between  200  and  300  pounds.  From  experi- 
ments conducted  by  the  bureau,  in  which  the  sumac  was  collected 
by  an  experienced  gatherer,  it  has  been  estimated  that  the  following 
amounts  of  sumac  (leaves,  leaf  stems,  and  stalk  combined)  can  be 
gathered  in  one  eight-hour  day  by  an  energetic  man,  provided  the 
stand  is  good,  so  that  little  time  is  lost  in  going  from  one  patch  to 
another : 

Dwarf,  728  pounds  green ;  loss  of  water  in  curing,  54  per  cent ;  cured  sumac, 
335  pounds.1 

White,  1,744  pounds  green ;  loss  of  water  in  curing,  67  per  cent ;  cured  suinac, 
576  pounds. 

Staghorn,  952  pounds  green  ;  loss -of  water  in  curing,  58  per  cent ;  cured  sumac, 
400  pounds. 

Where  the  stand  is  scattering  or  the  gatherer  is  slow,  the  quantity 
gathered  will  be  less,  but  in  no  case  should  an  able-bodied  man  be 
satisfied  with  less  than  200  pounds  of  cured  sumac  (leaves  and  stalks) 
from  his  day's  work. 

In  those  sections  where  black,  or  dwarf,  sumac  grows  plentifully, 
exceptionally  high  wages  can  be  earned,  particularly  by  women, 
children,  and  the  older  men,  by  gathering  sumac.  Spare  time  during 
July  and  August,  which  usually  is  a  comparatively  inactive  period 
on  the  farm  in  the  sumac-growing  sections,  can  be  profitably  em- 
ployed in  this  way.  By  gathering  and  carefully  curing  sumac,  at  $1 

1  The  dwarf  sumac  was  more  scattered  than  the  other  two  varieties.  This  may  account 
for  the  comparatively  low  figures  for  this  species. 


AMERICAN   SUMAC. 


per  hundred  pounds,  any  active  gatherer  can  make  from  $2  .to  $3 
a  day,  while  at  $2  per  hundred  pounds  he  can  earn  from  $4  to  $6 
a  day. 

GATHERING  AND  CURING. 

The  general  practice  folloAved  in  gathering  is  to  break  or  cut  (only 
the  black  can  be  broken  readily)  the  new-growth  stalk  just  below  the 
lowest  leaf  stem.  Sumac  never  should  be  allowed  to  wilt  in  the  sun 
for  more  than  a  lew  hours.  It  should  be  hauled  to  a  barn  and 
spread  on  the  clean  floor  in  a  layer  from  1  to  3  feet  deep,  or  on  racks 
which  permit  the  circulation  of  air  underneath.  The  sumac  must- 
be  turned  once  or  twice  each  day  for  a  week,  to  aid  in  the  drying 
and  to  prevent  the  leaves  from  molding.  The  brightest  sumac  is 
not  allowed  to  wilt  in  the  sun,  but  is  spread  at  once  on  racks  in 
the  barn  or  under  cover.  This  method  aids  materially  in  producing 
sumac  of  the  lightest  and  best  color. 

LOSS  IN  CURING  AND  HANDLING. 

Experienced  gatherers  estimate  that  100  pounds  of  green  sumac 
makes  only  from  40  to  50  pounds  of  the  cured  sumac.  There  is  still 
further  loss  in  weight  between  the  time  of  purchase  by  the  dealer 
and  the  time  of  sale,  due  largely  to  loss  of  moisture,  still  present 
because  of  incomplete  drying,  to  falling  of  leaves,  and  to  the  re- 
moval of  adhering  dirt.  This  loss  between  the  purchase  and  sale 
by  the  dealer  varies  in  amount  from  5  to  15  pounds,  thus  making  a 
total  loss  in  weight  of  from  60  to  75  pounds  per  hundred  pounds 
of  the  original  green  sumac. 

Results  of  laboratory  experiments  on  the  curing  of  sumac  (leaves, 
leaf  stems,  and  stalks),  given  in  Table  3,  show  losses  while  curing 
which  agree  well  with  those  estimated  by  gatherers. 

TABLE  3. — Loss  of  moisture  in  curing  sumac  (collected  September  28,  1916). 


Species. 

Duration 
of  drying. 

Loss  of 
moisture. 

Dwarf 

Days. 
5 

Per  cent. 
50.5 

White  

25 
49 

5 

53.2 
53.6 

63.9 

Staghorn  

25 
49 

5 

66.1 
66.6 

55.5 

25 
49 

57.3 

57.8 

There  is  reason  to  believe  that  the  loss  in  curing  on  the  farm  is  not 
so  great  as  the  loss  observed  in  the  bureau's  experiments,  where  the 
sumac  dried  out  very  thoroughly. 


8  BULLETIN   706,   U.   S.   DEPARTMENT   OF   AGRICULTURE. 

PREPARATION   FOR    TRANSPORTATION. 

Sumac  received  by  the  dealers  from  the  farmers  usually  comes  in 
bags,  or  is  handled  loose  in  wagonloads  like  hay,  and  in  many  in- 
stances may  have  been  hauled  as  far  as  20  miles.  Many  farmers  pre- 
fer to  deliver  the  sumac  in  wagonloads,  as  they  claim  that  too  much 
time  is  consumed  by  putting  it  up  in  bags.  Since  the  sumac  becomes 
very  brittle  when  dried  and  the  leaflets  are  easily  broken  from  the 
leaf  stems,  much  loss  occurs  in  handling  it  loose,  and  the  gatherer  can 
make  more  by  bagging  his  sumac,  packing  each  bag  as  full  as  possible. 
These  bags  cost  the  dealers  8  to  9  cents  each,  but  are  usually  furnished 
without  cost  to  the  gatherers.  Some  gatherers,  after  drying  the 
sumac,  flail  off  the  leaves  and  pack  them  in  bags  for  shipment. 
Seventy-five  pounds  should  be  packed  into  a  4-bushel  bag. 

From  the  small  dealers  to  the  extract  manufacturers  the  sumac  is 
usually  handled  in  bags  or  bales.  The  cost  of  baling  is  about  10 
cents  per  hundredweight. 

PRICES  PAID  GATHERERS  AND  DEALERS. 

During  the  seasons  of  1918  and  1919  in  eastern  Virginia  the 
gatherers  received  from  $1.25  to  $1.50  per  100  pounds  in  trade  from 
the  dealers.  The  extract  manufacturers  furnished  bags  for  use  in 
hauling  and  shipping  the  cured  sumac.  The  extract  makers  paid 
$1.65  per  100  pounds  for  the  bagged  material,  which  in  this  region 
includes  some  new-groAvth  stalks  as  well  as  the  leaves  and  leaf  stems. 
In  1919  in  northern  West  Virginia  and  western  Maryland  the 
gatherers  received  $1.50  per  hundred  pounds  in  trade  from  the 
dealers.  In  1920,  the  price  rose  to  $2.00  per  hundred  pounds  at  the 
shipping  point. 

TANNIN  CONTENT. 

The  leaves  and  leaf  stems  together  of  the  three  most  important 
American  sumacs — dwarf,  white,  and  staghorn — when  air-dried 
contain  approximately  the  same  quanity  of  tannin — that  is,  from  20 
to  35  per  cent.1  The  leaves  of  fragrant  sumac  are  said  to  contain  13 
per  cent  tannin,  those  of  American  smoke-tree  21  per  cent,  and  those 
of  coral  sumac  8  per  cent.  Usually  the  quantity  of  tannin  appears 
to  be  somewhat  greater  later  in  the  season  than  in  June  and  early 
July.  The  leaves  contain  the  highest  percentage  of  tannin  after 
they  are  fully  grown  and  before  they  begin  to  turn  yellow  or  red. 

Analyses  made  in  the  Leather  and  Paper  Laboratory  of  the  Bureau 
of  Chemistry  of  various  samples  of  sumac  gathered  in  Virginia,  West 
Virginia,  Maryland,  and  Pennsylvania  gave  the  results  shown  in 
Table  4. 

1  These  figures  apply  more  particularly  to  Virginia,  West  Virginia,  Maryland,  and 
Pennsylvania  sumacs. 


Bui.  706,  U.  S.  Dept.  of  Agriculture. 


PLATE  I, 


GATHERING  DWARF  SUMAC,  THE  ONLY  KIND 
SUMAC  DEALERS  WANT. 


Bui.  706,  U.  S.  Dept.  of  Agriculture. 


PLATE  II, 


DWARF  SUMAC  LEAVES  AND  LEAF  STEMS. 

This  is  the  only  part  of  bush  that  is  of  value  to  the  extract  maker.  The  gatherer  should  receive 
from  35  to  45  per  cent  more  for  the  leaves  and  leaf  stems  than  for  the  leaves,  leaf  stems,  and 
stalks.  Note  the  peculiar  growth  along  the  leaf  stems  which  is  characteristic  of  dwarf  sumac. 


Bui.  706,  U.  S.  Dept.  of  Agriculture. 


PLATE  III. 


WHITE  SUMAC  LEAVES  AND  LEAF  STEMS. 


Bui.  706,  U.  S.  Dept.  of  Agriculture. 


PLATE  IV. 


STAGHORN  SUMAC  LEAVES  AND  LEAF  STEMS. 


Bui.  706,  U.  S.  Dept.  of  Agriculture. 


PLATE  V. 


POISON  SUMAC. 
Do  NOT  GATHER  THIS  KIND. 


AMERICAN   SUMAC.  9 

TABLE  4. — Tannin  content  of  samples  of  dwarf,  white,  and  staghorn  sumac. 


Species. 

Tannin  in  leaves  and  leaf 
stems. 

Tannin  in  stalks. 

Average. 

Maxi- 
mum. 

Mini- 
mum. 

Average. 

Maxi- 
mum. 

Mini- 
mum. 

Dwarf 

Per  cent. 
28.95 
25.41 
27.66 

Per  cent. 
35.03 

28.08 
30.59 

Per  cent. 
19.46 
21.35 
21.53 

Per  cent. 
7.77 
6.84 
7.07 

Per  cent. 
9.94 
7.30 
8.09 

Per  cent. 
5.09 
6.19 
6.45 

White 

Staghorn  

Dwarf  sumac,  it  will  be  seen,  contains  somewhat  more  tannin  than 
staghorn  or  white  sumac.  This  bears  out  in  a  general  way  the  state- 
ment of  buyers  in  eastern  Virginia,  though  this  difference  is  of  itself 
not  great  enough  to  justify  the  refusal  of  the  white.  The  sumac 
samples  analyzed  were  found  to  average  73.3  per  cent  leaves  and 
leaf  stems  and  26.7  per  cent  stalks.  The  variation,  however,  was 
marked,  extending,  in  the  case  of  the  leaves  and  leaf  stems,  from 
54  to  89  per  cent,  and,  for  the  stalks,  from  11  to  46  per  cent.  The 
large  proportion  of  stalks  indicated  by  the  percentage  last  given 
should  never  be  permitted.  Gatherers  must  break  the  stalk  close 
up  to  the  lowest  leaf  stem,  and  must  not  gather  the  long  stalk 
bare  of  leaves.  If  the  stalks  are  broken  close  to  the  leaf  stems,  the 
sumac  will  usually  meet  the  buyers'  demands.  Dealers  and  extract 
makers  should  insist  that  the  sumac  delivered  shall  not  have  more 
than  25  per  cent  of  stalks. 

The  portions  of  the  plant  usually  considered  of  value  for  tanning 
and  dyeing  purposes  are  the  leaves  and  leaf  stems,  although,  as 
shown  in  Table  4,  the  stalks  contain  from  5  to  10  per  cent  tannin,  an 
amount  entirely  too  large  to  discard  after  the  trouble  and  expense 
of  collecting  and  hauling  to  market  has  been  incurred.  This  tannin 
should  be  recovered,  as  an  extract  could  be  made  from  the  stalks 
and  off-colored  leaves  that  would  be  satisfactory  for  tanning  and 
dyeing  purposes  when  color  is  not  the  primary  consideration. 

SUMAC  EXTRACT. 

It  has  been  the  experience  of  sumac  extract  makers  that  sumac 
from  Virginia,  West  Virginia,  North  Carolina,  and  western  Ken- 
tucky contains  the  most  tannin  and  yields  more  extract  than  that 
from  the  States  farther  north.  For  that  reason,  they  prefer  to  buy 
their  sumac  from  those  southern  States. 

Formerly  the  users  of  domestic  sumac  bought  the  leaves  or  ground 
sumac,  which  is  the  sumac  leaf  ground  to  a  coarse  powder,  and  made 
their  own  liquors  for  tanning  or  dyeing  from  these  materials.  Re- 
cently the  grinding  of  sumac  has  decreased,  and  users  have  bought 
sumac  extract  instead.  The  price  of  domestic  sumac  extract,  which 


10 


BULLETIN   706,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 


contains  usually  from  22  to  24  per  cent  of  tannin  and  is  sold  on  the 
basis  of  its  strength,  has  increased  materially  in  the  past  few  years. 
For  42°  extract  the  quoted  price  a  pound  was:  In  1914,  about  3| 
cents;  in  1915,  from  3|  to  9  cerfts;  in  1916,  from  5J  to  10  cents;  in 
1917,  from  4J  to  5  cents ;  in  1918,  from  4J  to  5  cents ;  and  in  August, 
1920,  from  7  to  8  cents. 

A  pound  of  extract  contains  approximately  the  same  amount  of 
tannin  as  a  pound  of  properly  gathered  and  cured  leaf.  In  making 
the  extract  the  tannin  is  extracted  with  large  quantities  of  water 
which  must  be  evaporated  in  expensive  copper  pans  under  skilled 
supervision  and  at  some  expense  for  fuel.  When  the  extract  is  to  be 
used,  as  much  or  more  water  than  was  evaporated  in  making  it  is 
added  to  secure  a  tanning  or  dyeing  solution  of  the  desired  strength. 
The  consumer,  however,  often  prefers  to  use  the  extract,  rather  than 
to  make  his  cwn  liquor  from  the  leaf. 

DISPOSAL  OF  EXTRACTED  MATERIAL. 

So  far  as  can  be  learned,  no  really  satisfactory  method  of  disposing 
of  the  extracted  leaves  is  in  general  use.  The  material  is  placed  in 
large  piles  or  ricks,  or  taken  to  fill  in  waste  places.  A  small  quantity 
is  used  on  farm  land  as  a  top-dressing  to  be  plowed  under.  Analyses 
of  the  commercially  extracted  material  given  in  Table  5  show  its 
fertilizing  value. 

* 

TABLE  5. — Fertilizing  value  of  commercially  extracted  sumac  leaves  and  leaf 

stens  and  stalks. 


Aj 

h. 

Sample 
No. 

Part  of  plant. 

Mois- 
ture. 

Cal- 
cium 
oxid. 

Potas- 
sium 
oxid. 

phorus 
pen- 
toxid. 

Total. 

Cal- 
cium 
oxid. 

Potas- 
sium 
oxid. 

Phos- 
phorus 
pen- 
toxid. 

32479  

Leaves  and  leaf 
steins 

Per  cent. 
5  70 

Per  cent. 
1  66 

Per  cent. 
0  11 

Per  cent. 
0  23 

Per  cent. 
5  13 

Per  cent. 
32  36 

Per  cent. 
2  14 

Per  ctnt. 
4  48 

32482... 

..  ..do  

5.33 

1.95 

.09 

.20 

5.32 

36.65 

1.69 

3.76 

32479 

Stalks 

4.59 

1.31 

39 

15 

3  43 

38  19 

11  37 

4  37 

32482  

do  

4.59 

1.44 

.17 

.11 

3.24 

41.36 

5.24 

3.39 

Examination  of  a  number  of  unextracted  sumac  samples  gave: 
Ash,  4  to  7.5  per  cent;  potassium  oxid,  1.18  to  2.15  per  cent.  Ttie 
ash  of  these  samples  contained  from  25  to  30  per  cent  of  potassium 
oxid. 

Comparison  of  the  percentage  of  potassium  oxid  (K2O)  in  the 
original  material  and  in  the  water  extract,  as  obtained  for  the  tannin 
analysis,  shows  that  although  the  unextracted  sumac  contains  rather 
high  percentages  of  potassium  oxid,  this  is  almost  entirely  removed 
on  extraction.  These  experiments  were  made  on  finely  ground  su- 


AMERICAN   SUMAC.  11 

mac  leaves  and  leaf  stems,  whereas  in  commercial  practice  the  ex- 
traction generally  is  made  on  the  imground  leaves  and  stalks,  and 
consequently  is  not  so  thorough,  especially  in  the  case  of  the  larger 
stalks.  This  practice  of  making  extraction  on  the  unground  leaves 
and  stalks  undoubtedly  accounts  for  the  comparatively  high  per- 
centages of  potassium  oxid  in  the  samples  of  commercially  extracted 
stalks,  analyses  of  which  are  given  in  Table  5. 

Except  for  the  organic  matter  which  it  contains,  extracted  sumac 
has  comparatively  little  value  for  the  farmer.  However,  in  sections 
where  sumac  is  gathered,  where  the  land  is  usually  deficient  in  or- 
ganic matter,  the  extracted  material  can  be  profitably  hauled  a  mile 
or  two,  especially  if  before  scattering  on  the  land  it  can  be  mixed 
and  rotted  with  barnyard  manure. 

CAUSES  OF  POOR  QUALITY  IN  SUMAC. 

Lack  of  care  and  attention  to  details  in  gathering  and  curing 
results  in  sumac  of  inferior  quality.  Undue  exposure  to  the  sun, 
any  exposure  to  dew  or  rain,  heating  and  molding  in  deep  layers, 
arid  failure  to  turn  once  a  day  while  curing  cause  decided  darkening 
of  the  leaves  and  materially  reduce  the  percentage  of  tannin.  The 
presence  of  stalks,  red  leaves,  blooms,  or  berries  in  cured  sumac  is 
objectionable,  because  they  produce  an  undesirable  color  on  leather. 
Furthermore,  since  the  stalks  contain  only  about  one-fourth  as  much 
tannin  as  the  leaves,  their  presence  gives  the  mixture  a  lower  tannin 
content.  The  presence  of  dirt  or  sand  in  cured  sumac  also  is  ob- 
jectionable, for  it  increases  the  weight  without  increasing  the  tannin 
content,  and  leathers  tanned  with  such  sumac  will  darken  because 
of  the  iron  present. 

COOPERATION  FOR  BETTER  SUMAC. 

One  of  the  objects  of  this  bulletin  is  to  point  out  the  necessity  for 
helpful  cooperation  between  gatherers,  dealers,  and  extract  makers, 
with  a  view  to  the  production  of  higher  grade  sumac  and  sumac 
extracts  and  the  payment  of  higher  prices  to  the  gatherers  for  better 
sumac.  This  cooperation  can  be  successfully  maintained  only  if  it 
is  mutually  beneficial.  The  initiative  and  success  rest  with  the  final 
buyers,  the  extract  makers,  who,  by  offering  a  bonus  for  "extra" 
quality  sumac,  can  encourage  the  gatherers  to  make  special  efforts 
to  produce  a  high-grade,  bright,  clean  product.  It  is  suggested 
that,  for  the  information  and  guidance  of  gatherers,  dealers  and 
buyers  keep  on  hand  suitable  samples,  one  to  be  known  as  "  Stand- 
ard," for  which  they  will  pay  the  regular  price,  and  another  as 
"  Extra,"  for  which  a  bonus  will  be  paid.  Sumac  materially  below 


12  BULLETIN   706,   U.   S.   DEPARTMENT   OF   AGRICULTURE. 

"  Standard  "  in  color  or  quality  should  be  bought  only  at  a  reduc- 
tion. If  the  directions  for  gathering  and  curing  given  in  this 
bulletin  are  carefully  followed,  no  sumac  below  "  Standard "  will 
be  produced,  while  much  of  it  will  be  of  "  Extra  "  quality. 

DIRECTIONS  FOR  GATHERING  AND  CURING. 

In  order  to  obtain  sumac  of  the  best  quality,  both  as  to  color  and 
percentage  of  tannin,  carefully  follow  these  directions: 

Gather  only  dwarf,  or  black  sumac  (PL  II).  Break  the  stalk 
bearing  the  leaves  and  leaf  stems  just  below  the  lowest  leaf  stem; 
or,  better,  gather  only  the  leaves  and  leaf  stems,  throwing  away  all 
blooms  or  berries.  Harvest  during  July,  August,  and  Sep- 
tember. Do  not  collect  red  or  yellow  leaves.  As  soon  as  gathered, 
place  the  sumac  in  the  shade  or  under  a  canvas  cover,  which  permits 
the  air  to  get  to  it,  and  prevents  undue  exposure  to  the  sun.  Do 
not  allow  it  to  be  wet  by  dew  or  rain,  and  at  the  end  of  each  day 
haul  the  gathered  sumac  to  a  barn  or  open  shed,  wrhere  it  should 
be  spread  in  layers  not  over  L|  feet  deep  upon  a  clean  floor,  or  upon 
open  racks  which  will  permit  ready  access  of  air.  Do  not  allow 
the  gathered  sumac  to  come  in  contact  with  the  bare  ground  at  any 
time,  as  dirt  injures  its  quality.  Turn  the  layers  over  once  or  twice 
daily  for  from  one  to  two  weeks,  or  until  thoroughly  dry.  In  case 
stalks  have  been  gathered  with  the  leaves,  remove  the  stalks  by 
flailing  and  forking  out.  The  leaves  thus  prepared  should  be  of 
a  uniformly  light-green  color.  Pack  tightly  in  bags  and  keep  in 
a  well- aired,  dry  loft  until  sold. 

BUYERS  OF  SUMAC. 

Sumac,  when  properly  cured,  usually  can  be  sold  to  merchants  in 
towns  or  cities  near  the  place  where  it  has  been  gathered,  or  it  can  be 
sold  directly  to  manufacturers  who  buy  sumac  for  grinding  or  for 
the  preparation  of  sumac  extract.  Before  starting  to  gather,  how- 
ever, the  gatherer  should  have  a  definite  understanding  and  contract 
with  the  dealer  as  to  the  quantity  which  he  will  buy  from  him ;  the 
price  which  will  be  paid ;  how  the  sumac  is  to  be  delivered ;  arrange- 
ments for  a  supply  of  bags,  if  it  is  to  be  delivered  in  bags ;  and  espe- 
cially as  to  the  extra  price  to  be  paid  for  exceptionally  bright,  well- 
cured  sumac.  If  the  names  of  dealers  are  not  obtainable  by  inquiry 
of  merchants,  hide  dealers,  or  others  in  near-by  towns  or  cities,  this 
information  can  be  obtained  from  the  various  State  agricultural 
experiment  stations  or  from  the  Bureau  of  Chemistry,  United  States 
Department  of  Agriculture,  Washington,  D.  C. 


AMERICAN   SUMAC.  13 

SUMMARY. 

Imported  sumac  is  scarce  and  high  priced.  Domestic  sumac,  if 
properly  gathered  and  cured,  can  be  largely  substituted  for  im- 
ported, and  should  bring  better  prices  than  domestic  sumac  as  now 
cured.  Sumac  grows  wild  and  abundantly  on  uncultivated  lands, 
particularly  on  those  east  of  the  Mississippi  River.  Country  people, 
especially  the  elderly,  and  women  and  children,  can  earn  good  wages 
from  July  to  September  by  gathering  and  curing  sumac. 

Practically  the  only  kind  of  sumac  gathered  in  this  country  is 
dwarf,  or  black  (Rhm  copallina) . 

Before  beginning  to  gather,  consult  your  local  merchants  or  State 
experiment  station  to  ascertain  the  names  and  addresses  of  buyers 
of  sumac  and  of  sumac  extract  makers.  Be  sure  to  arrange  fully 
and  clearly  with  the  dealers  as  to :  (1)  The  quantity  which  they  will 
buy  from  you;  (2)  a  supply  of  bags;  (3)  the  price  per  hundred 
pounds ;  and  especially  (4)  an  extra  price  for  well- cured  sumac  leaf. 

In  gathering,  break  the  stalk  close  up  to  the  leaf  stem  and  do  not 
include  long  bare  stalks.  Do  not  gather  blooms,  berries,  or  yellow 
or  red  leaves.  Do  not  allow  the  gathered  sumac  to  scald  in  the  sun 
or  to  become  wet  with  either  dew  or  rain.  Cure  in  the  barn  or 
under  cover  on  a  clean  floor.  Turn  once  or  twice  a  day  until  the 
sumac  is  thoroughly  dry  and  crisp.  Pack  and  ship  only  in  full, 
tightly  packed  bags.  Do  not  bale,  and  do  not  allow  dirt,  stones,  or 
pieces  of  iron  to  get  into  the  bags.  Such  practices  ultimately  result 
in  a  loss  to  the  gatherer. 

As  now  prepared  for  the  market,  domestic  sumac  contains  less 
tannin  than  and  is  greatly  inferior  in  color  to  imported  Sicilian  sumac. 

Proper  gathering  and  curing  will  greatly  improve  the  color  of  the 
domestic  sumac  leaf.  Such  leaf  contains  from  25  to  30  per  cent  of 
tannin,  which  is  practically  as  much  as  the  Sicilian  leaf. 

A  pound  of  domestic  sumac  extract,  of  42°  strength  and  contain- 
ing from  22  to  24  per  cent  of  tannin,  was  quoted  in  1914  at  about 
3|  cents;  in  1915,  from  3f  to  9  cents;  in  1916  from  5J  to  10  cents;  in 
1917,  from  4J  to  5  cents;  in  August,  1918,  4|  to  5  cents;  and  in 
August,  1920,  from  7  to  8  cents. 

The  development  of  the  American  sumac  industry  and  the  pro- 
duction of  bright,  uniformly  and  properly  cured  domestic  sumac  can 
be  accomplished  only  through  the  earnest  and  whole-hearted  cooper- 
ation of  the  extract  makers,  merchants,  buyers,  and  gatherers.  Ex- 
tract makers  and  buyers  must  make  every  effort  to  stimulate  the 
proper  gathering  and  curing  by  offering  better  prices  and  through 
careful  instructions  in  proper  methods  of  gathering,  curing,  and 
packing.  The  gatherers  must  help  by  following  carefully  the  direc- 
tions set  forth  in  this  bulletin  and  by  working  harmoniously  with  the 
buyers. 


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